Analysis of Common Faults of Tractor Hydraulic Suspension System
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During the use of the tractor, the hydraulic suspension system often malfunctions. The following analysis of the frequently occurring failures of the hydraulic suspension system is performed from different angles. 1. The gear pump does not absorb oil or insufficient oil. Phenomenon: Suspended implements are raised or cannot be lifted; the system pressure is unstable during the process of raising the implements, causing jitter or noise; air bubbles in the tank or pipeline; the temperature of the pump increases. Reason: oil level is too low or no oil; oil viscosity is too large (may be the wrong oil number or oil temperature is too low); oil filter or suction pipe plugged; suction port is not tightened, or the seal ring is damaged or leaked Install the suction pipe into the air; inhale the air due to the damage of the self-tightening oil seal in the front cover of the gear pump. 2. Insufficient oil supply or insufficient pressure in the gear pump: The oil suction condition is normal, but the hanging implements are slowly raised or cannot be lifted; the lifting condition is better when the implements are not in use, but the temperature of the oil pump rises quickly. Reasons: 1 bushing end wear too much, resulting in increased axial clearance, small sealing ring is not tight because of the screw is screwed into the gap and damage, so that high and low areas collusion. The sealing of the mating face of the 2 sleeve and the gear is destroyed and an internal leakage occurs. 3 The damage or failure of the small inner seal ring in the pump has caused the seal and pressure-reducing function of the oil pump end to be damaged, and the internal leakage is serious. The rubber clogging of the 4-sleeve waist is retracted into the hole, and the pressure-reducing action of the seal is not achieved. The pressure oil leaks seriously. 5 The tight oil seal in the front cover of the pump is damaged, causing oil leakage. 3. Gear Pump Burnout Phenomenon: Pump body temperature screams at the same time, and the engine load suddenly increases or even shuts off. Reasons: 1 The gear pump can't suck or absorb enough oil for a long period of time. Due to the lack of internal lubrication, it can cause friction and cause burnout. 2 The gear pump is often overloaded due to use of the lifter, improper adjustment, or blockage of the hydraulic system, failure of the safety valve or back generation. 3 The assembly is too tight and damaged due to excessive rotation resistance. 4. Hydraulic riser failure Symptoms: Lifter operation failure, oil leakage, and check valves. When the valve failure occurs, the control valve is stuck in a position in the valve hole, causing hydraulic oil working oil circuit abnormality, making the agricultural implement unable to move up and down. Cause: The riser operation failure is generally due to the failure of the connection between the joystick and the slide valve. Sometimes due to wear and spring failure, the positioning of the joystick and failure of the limit position may also be caused. Regarding the reason for the oil leakage, the inner leakage of the distributor was mainly caused by the poor seal between the valve and the valve hole or the valve seat, and the outer leakage was mainly caused by the damage of the seal old warb. In addition, excessive wear on the working surfaces of the piston and cylinder, and aging of the rubber seal and the year apron can also cause serious oil leakage. The main reason for causing the valve may be improper maintenance, hydraulic oil is dirty, the clearance gap between the valve and the valve hole is too small, or the valve and the valve hole are rusted. 5. Phenomenon: Oil leakage from the oil cylinder and the piston stuck in the cylinder, so that the agricultural tool cannot lift. Reason: oil cylinder oil leakage is often due to piston and cylinder wear too much or rubber seal failure caused by; piston is used in the cylinder is mainly due to long-term without the use of fuel tank, the surface of the oil tank cement film stuck and seal the seal; In addition, the metal piston ring and the cylinder surface rust corrosion, or impurities, foreign matter snap into the gap, it will also cause the piston stuck to failure. 6. The hydraulic suspension system cannot be upgraded or can not normally raise the agricultural implement phenomenon: after the control handle is moved to the lifting position, the agricultural implement cannot be upgraded; sometimes the lifting is slow and the shaking phenomenon occurs; the lifting can be performed quickly without hanging the agricultural implement; sometimes the hydraulic system is used in the lifting process. Noise is generated in the system, and heating sometimes occurs. Causes and inspection methods: Failure of the control mechanism can be judged by hand feeling method. If the oil pump is accompanied by noise and heat when lifting, it may be that it is not able to suck or to suck. If a large amount of air bubbles are found in the fuel tank, it indicates that there is a leak in the suction line of the oil pump. If the gear oil pump leaks, the normal pressure cannot be established, or the plunger pump and the pump body of the piston pump are seriously worn, resulting in insufficient oil supply. The oil circuit can be disassembled in the appropriate location, and the crankshaft can be rotated to observe the oil pump pump condition to judge. . If a pressure gauge or a dedicated tester is used for the test, the judgment is more accurate. When the safety valve is opened and does not return, or if the seal between the valve body and the valve seat is poor, it can also lead to serious oil leakage. At this point you can use the change method to judge. If the cylinder is seriously leaking oil, use the manpower to help raise the agricultural tool. Then, turn the joystick to the neutral position and cut off the power of the pump to observe the automatic settlement of the agricultural machine to determine the fault. 7. The farm tool cannot land: The handle is pulled to the down position, and the implement remains at its original height and cannot land. Causes and inspection methods: When the joystick loses its function, it is mostly because the connection between the positioning block and the handle shaft or the control valve is broken. At this time, although the handle is in a descending position, the control valve does not move and the oil path cannot be lowered. The agricultural implement cannot land. For this kind of failure, it is generally judged by hand-feeling method. If the adjustment of the descending speed is not turned on, the adjusting bolt can be screwed clockwise inward to make the valve open safely and observe whether the implement is landed or not, and in order to make the unit safe to run on the road or other needs of the East Road, when the implement is raised, often Use the locking shaft to lock the inner lift arm in the lifting state. Before the farmer with the handle is turned, the lock shaft is not pulled to the disengagement position, and the farm implement cannot land at this time. In this regard, it is possible to pull the gold tight shaft to the disengaged position and observe whether the agricultural implement has landed. If the piston is in a raised position but the card is not serious, manpower can be used to help the implement land. If the card is very dead, do not forcefully press down on the tool to avoid damage to the tool. 8. Farm implements do not maintain the state of transport phenomenon: When the implement is raised to the transport height, and the joystick automatically returns to the neutral position, the phenomenon of automatic downward settlement of the implement occurs. Causes and inspection methods: Due to excessive wear of the control valve or valve and the valve hole, causing the increase in the clearance, resulting in oil leakage, so that in the neutral position can not be tightly sealed in the pressure oil within the cylinder; In addition, the cylinder leakage is serious, and Internal leakage of the pressure oil with the cylinder is generally not easy to judge from the outside, and it needs to be disassembled and checked.